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2015:groups:higgs:pseudoxsecs [2015/06/09 11:14] tania.robens [Discussion on Pseudo Observables/Cross Sections for Higgs Measurements] |
2015:groups:higgs:pseudoxsecs [2015/06/28 19:25] frank.tackmann |
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- | ====== Discussion on Pseudo Observables/Cross Sections for Higgs Measurements ====== | + | ====== Discussion on Pseudo Observables/Simplified Cross Sections for Higgs Measurements ====== |
//If you are interested in contributing, please sign up [[2015:groups:topicsignup:pseudoxsecs|here]].// | //If you are interested in contributing, please sign up [[2015:groups:topicsignup:pseudoxsecs|here]].// | ||
+ | //This twiki page is closed -- session 2, we welcome your comments, and in particular suggestions on the BSM-motivated regions including proposals for the "BSM jokers" [[2015:groups:pseudoxsecsBSM|here]].// | ||
+ | |||
+ | //[Update]//: For an overview talk with some more details see [[https://indico.cern.ch/event/399923/session/3/contribution/20/material/slides/0.pdf|here]] (corresponding to 2nd iteration below). | ||
- | T. Robens | ||
==== Goal: ==== | ==== Goal: ==== | ||
- | Define "pseudo-cross sections" as general framework for Higgs measurements and combination of decay channels. | + | Define "simplified cross sections" as general framework for Higgs measurements and combination of decay channels. |
* Provide "measurement interface" between raw experimental categories and final interpretation. | * Provide "measurement interface" between raw experimental categories and final interpretation. | ||
Line 15: | Line 17: | ||
* Can then be interpreted in SM (analogous to current mu fits) or different BSM scenarios (Higgs-EFTs or specific models) | * Can then be interpreted in SM (analogous to current mu fits) or different BSM scenarios (Higgs-EFTs or specific models) | ||
- | ==== Guiding principles for definition of pseudo-cross sections: ==== | + | ==== Guiding principles for definition of simplified cross sections: ==== |
* Should be reasonably well constrained/measured | * Should be reasonably well constrained/measured | ||
* Important to think which phase-space regions are important to separate out from the theory side | * Important to think which phase-space regions are important to separate out from the theory side | ||
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== Notes: == | == Notes: == | ||
- | * Does not replace measurement of fiducial/differential cross sections in gammagamma and | + | * Does not replace measurement of fiducial/differential cross sections in gammagamma and ZZ |
* Allows maximizing experimental sensitivity, e.g. can still use MVA-based selections, ... | * Allows maximizing experimental sensitivity, e.g. can still use MVA-based selections, ... | ||
* Still important to ensure that MVAs do not introduce uncontrolled theory systematics (e.g. check which phase space regions get selected) | * Still important to ensure that MVAs do not introduce uncontrolled theory systematics (e.g. check which phase space regions get selected) | ||
- | * Some of the observables might also be | + | * Some of the (pseudo)observables might also be |
* limits | * limits | ||
* asymmetries | * asymmetries | ||
* continuous parameters for kinematic deviations (e.g. CP odd admixture) | * continuous parameters for kinematic deviations (e.g. CP odd admixture) | ||
* Definition can evolve | * Definition can evolve | ||
- | * Can split into more fine-grained pseudo-cross sections once statistics allows (previous measurements remain useful) | + | * Can split into more fine-grained bins once statistics allows (previous measurements remain useful) |
== Specific points for further discussion: == | == Specific points for further discussion: == | ||
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==== 1st iteration ==== | ==== 1st iteration ==== | ||
- | of possible pseudo-cross sections (in the following "bins"), to be continued ... | + | of possible cross sections (in the following "bins"), to be continued ... |
For 2nd iteration: Reduce number of bins, classify according to importance/feasibility | For 2nd iteration: Reduce number of bins, classify according to importance/feasibility | ||
- | Note: "ggF", "VBF", ... describe the kinematics/topology, not necessarily only the SM production mode. (Can think of it as "simplified kinematic model".) | + | == Notes: == |
+ | |||
+ | * "ggF-topology", "VBF-topology", ... describe the SM-like kinematic topology, not necessarily only the SM production mode. So one can think of it as using the SM itself as a "simplified kinematic model". (In practice, on the experimental side the corresponding SM processes are used to evaluate and unfold the acceptance corrections.) | ||
* everything is meant schematically, all numbers are just for illustration | * everything is meant schematically, all numbers are just for illustration | ||
* In the future, can add additional non-SM-like kinematic templates (e.g. CP-odd ggF) | * In the future, can add additional non-SM-like kinematic templates (e.g. CP-odd ggF) | ||
- | == ggF-like == | + | == ggF-topology == |
=0j \\ | =0j \\ | ||
=1j, separate bin for pTj>~100 GeV (or pTH>~100 GeV) \\ | =1j, separate bin for pTj>~100 GeV (or pTH>~100 GeV) \\ | ||
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* inputs: gammagamma, ZZ, WW, tautau (for 1j > 100 GeV, 2j VBF and >=3j) | * inputs: gammagamma, ZZ, WW, tautau (for 1j > 100 GeV, 2j VBF and >=3j) | ||
- | == VBF-like == | + | == VBF-topology == |
main: mjj >~ 300 GeV (and have some rest 120-300 to not lose any region) \\ | main: mjj >~ 300 GeV (and have some rest 120-300 to not lose any region) \\ | ||
more possibilities: mjj, pTj, Deltaetajj \\ | more possibilities: mjj, pTj, Deltaetajj \\ | ||
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* inputs: gammagamma, ZZ, WW, tautau, bbbar | * inputs: gammagamma, ZZ, WW, tautau, bbbar | ||
- | == VH-like (V -> hadrons) == | + | == VH-topology (V -> hadrons) == |
mjj 70 - 120 GeV \\ | mjj 70 - 120 GeV \\ | ||
m(VH) = [0, 300, 600, inf] (more ideal from theory side) \\ | m(VH) = [0, 300, 600, inf] (more ideal from theory side) \\ | ||
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* Need to think about how to best deal with the overlap between VBF and VHhad | * Need to think about how to best deal with the overlap between VBF and VHhad | ||
- | == VH-like (V -> leptons) == | + | == VH-topology (V -> leptons) == |
keep the Z and W separately: Z->ll, Z->nunu, W->lnu \\ | keep the Z and W separately: Z->ll, Z->nunu, W->lnu \\ | ||
same bins as for VHhad (need to see how well this works with neutrinos) \\ | same bins as for VHhad (need to see how well this works with neutrinos) \\ | ||
- | * inputs: bbbar, gamgam, ZZ, WW, tautau | + | * inputs: bbbar, gamgam, ZZ, WW, tautau |
- | == gg->ZH-like == | + | == gg->ZH-topology == |
as for VH, likely fewer bins (more relevant for higher pT(V), m(VH)) \\ | as for VH, likely fewer bins (more relevant for higher pT(V), m(VH)) \\ | ||
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== tHW, tHjq == | == tHW, tHjq == | ||
inclusive and then as few kinematic parameters as possible | inclusive and then as few kinematic parameters as possible | ||
+ | |||
+ | |||
+ | ==== 2nd iteration ==== | ||
+ | |||
+ | == Notes: == | ||
+ | |||
+ | * jets are assumed as anti-kt 0.4, |eta|<4-5, pT>=25-30 GeV | ||
+ | * bins are exclusive (in the selection, start from the lowest bin on the list) | ||
+ | |||
+ | * "ggF-topology", "VBF-topology", ... describe the SM-like kinematic topology, not necessarily only the SM production mode. So one can think of it as using the SM itself as a "simplified kinematic model". (In practice, on the experimental side the corresponding SM processes are used to evaluate and unfold the acceptance corrections.) | ||
+ | * explicit numbers are only meant as ball-park numbers | ||
+ | |||
+ | Proposal for two reduced scenarios, "small" and "medium", trying to take into account feasibility with current statistics, theoretical uncertainties, and sensitivity to BSM. | ||
+ | |||
+ | |||
+ | == ggF-topology == | ||
+ | |||
+ | SMALL\\ | ||
+ | 0j\\ | ||
+ | >=1j, split into pTH < = mH, pTH = mH - 200 GeV, pTH > 200 GeV (highest bin for BSM)\\ | ||
+ | >=2 VBF (mjj, Deltaetajj cuts as for VBF), split into =2 and >=3 by a pTHjj cut\\ | ||
+ | |||
+ | |||
+ | MEDIUM\\ | ||
+ | split pTH > 200 GeV into 200 GeV - high, and > high\\ | ||
+ | split >=1j to =1j and >=2j (with the pTH splitting)\\ | ||
+ | |||
+ | |||
+ | == VBF-topology == | ||
+ | |||
+ | SMALL\\ | ||
+ | rest\\ | ||
+ | >=2j, with mjj and Deltaetajj cuts, split into =2 and >=3 by a pTHjj cut\\ | ||
+ | "high-q^2" bin (can be replaced by something else BSMy, could be high pTj1)\\ | ||
+ | |||
+ | MEDIUM\\ | ||
+ | allow for continuous parameter to allow for contribution of CP odd coupling | ||
+ | (interference is probably irrelevant, but could check)\\ | ||
+ | another "BSM joker" (TBD by session 2)\\ | ||
+ | |||
+ | |||
+ | == VH-topology == | ||
+ | |||
+ | SMALL\\ | ||
+ | exclusive in ll+nunu, lnu, had\\ | ||
+ | pT(V) = 0 - mH (low) and mH - inf (high)\\ | ||
+ | split high in =0j, >=1j\\ | ||
+ | pT(V) > 200 GeV (for BSM) | ||
+ | |||
+ | MEDIUM\\ | ||
+ | split ll and nunu\\ | ||
+ | split low pT(V) bin into 0j and >=1j\\ | ||
+ | |||
+ | |||
+ | == gg->VH-topology == | ||
+ | |||
+ | same as for VH, if completely degenerate can give the sum of VH and gg->VH | ||
+ | |||
+ | |||
+ | == ttH == | ||
+ | |||
+ | SMALL\\ | ||
+ | 1 incl bin\\ | ||
+ | |||
+ | MEDIUM\\ | ||
+ | split into 0j, >=1j additional jets (with a rather high pT cut, maybe 50-100 GeV?)\\ | ||
+ | add "BSM joker" (to be defined by session 2) | ||
+ | |||
+ | |||
+ | == bbH == | ||
+ | |||
+ | MEDIUM\\ | ||
+ | 1 incl bin | ||
+ | |||
+ | |||
+ | == tH == | ||
+ | |||
+ | MEDIUM\\ | ||
+ | 1 incl bin | ||